After completing its first year of observations in the southern sky, NASAs Transiting Exoplanet Survey Satellite has spotted some intriguing new exoplanets only 31 light-years away from Earth.美国宇航局的过境系由外行星测量卫星（TESS）在已完成对南半球天空的第一年观测后，找到了几颗距离地球仅有31光年的有意思的新系外行星。Multiple exoplanets -- planets orbiting stars outside our solar system -- were discovered orbiting an M-dwarf star, called GJ 357 in the Hydra constellation. The star is 40% cooler than our sun and only about a third of the suns mass and size. A study describing the three planets was published this week in the journal Astronomy Astrophysics.科学家找到了数颗环绕着长蛇座M矮星GJ 357运营的系外行星，系由外行星所指的是环绕太阳系外恒星运营的行星。这颗恒星的温度比太阳较低40%，质量和体积只有太阳的三分之一左右。一项叙述这三颗行星的研究本周公开发表在《天文学与天体物理学》期刊上。
The first exoplanet discovered around the star was GJ 357 b.科学家找到的首颗环绕这颗恒星运营的系外行星是GJ 357 b。The exoplanet is 22% larger and 80% more massive than Earth, making it a super-Earth. The researchers estimate that it has an average temperature of 490 degrees Fahrenheit. It completes one orbit around the star every 3.9 days.这颗系外行星体积比地球大22%，质量比地球低80%，使之沦为“超级地球”。
研究人员估算它的平均温度为490华氏度（约合254摄氏度）。这颗行星的公转周期为3.9天。We describe GJ 357 b as a hot Earth, said Enric Pallé, study co-author and astrophysicist at the Institute of Astrophysics of the Canary Islands. Although it cannot host life, it is noteworthy as the third-nearest transiting exoplanet known to date and one of the best rocky planets we have for measuring the composition of any atmosphere it may possess.“我们将GJ 357 b叙述为一个‘热地球’，”研究的合作者、加那利群岛天体物理研究所的天体物理学家恩里克·害怕佩说道。“尽管它无法支撑生命，但值得注意的是，它是迄今为止未知的‘第三近程’过境系由外行星，也是可以用来测量其享有的任何大气成分的最佳岩质行星之一。
”The researchers also discovered more signals of exoplanets in the system.研究人员还在星系中找到了更加多系外行星的信号。GJ 357 d, a super-Earth that is 6.1 times the Earths mass, is the most intriguing because it orbits the star at a distance where the temperature might be just right to support liquid water on the surface.另一颗“超级地球”GJ357d的质量是地球的6.1倍，最令其研究人员感兴趣，因为它环绕恒星运营的距离使其表面的温度有可能恰好适合液态水的不存在。GJ 357 d is located within the outer edge of its stars habitable zone, where it receives about the same amount of stellar energy from its star as Mars does from the Sun, said Diana Kossakowski, study co-author at the Max Planck Institute for Astronomy. If the planet has a dense atmosphere, which will take future studies to determine, it could trap enough heat to warm the planet and allow liquid water on its surface.“GJ 357 d坐落于其恒星宜居带上的外边缘，它从恒星接管到的能量与火星从太阳接管到的能量差不多，”马克斯普朗克天文研究所的研究年出版者戴安娜·科萨科夫斯基说道。
“如果这颗行星有密集的大气层，它可能会捕捉充足的热量使自身气候变化，表面就可以存留液态水，而否不存在大气层还必须更进一步研究。”The researchers dont know if the super-Earth is rocky like our own planet, but it orbits the star every 55.7 days and has a temperature of negative 64 degrees Fahrenheit. An atmosphere could cause it to be warmer.科学家尚能不确切这颗“超级地球”否和地球一样归属于岩质行星，但它的公转周期为55.7天，温度为零下64华氏度。如果行星上有大气层，温度不会更高。This is exciting, as this is humanitys first nearby super-Earth that could harbor life -- uncovered with help from TESS, said Lisa Kaltenegger, study author, associate professor of astronomy and director of Cornells Carl Sagan Institute. With a thick atmosphere, the planet GJ 357 d could maintain liquid water on its surface like Earth and we could pick out signs of life with upcoming telescopes soon to be online.研究报告的编写者、天文学副教授、康奈尔大学卡尔·萨根研究所所长莉萨·柯廷福说道：“这很令人兴奋，因为这是人类在TESS的协助下找到的第一颗有可能不存在生命的近距离‘超级地球’。
如果不存在密集的大气层，行星GJ357 d有可能像地球一样表面可存留液态水，我们也许可以通过将要上线的望远镜寻找生命的迹象。If GJ 357 d were to show signs of life, it would be at the top of everyones travel list—and we could answer a 1,000-year-old question on whether we are alone in the cosmos.“如果GJ 357 d行星上有生命迹象，它将沦为每个人旅行表格上的第一目的地，那个后遗症我们上千年的问题也许也将有答案，那个问题就是：人类是不是宇宙中唯一不存在的生命。”In the middle of those two planets is GJ 357 c. Its 3.4 times the mass of Earth and zips around the planet every 9.1 days, reaching a temperature of 260 degrees Fahrenheit.行星GJ357 c坐落于这两颗行星中间，质量是地球的3.4倍，公转周期为9.1天，温度超过260华氏度。
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